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Comment by coryrc | Hacker News Reader

I had an RV which was previously housing mice. After removing and Killz, it still smelled. Two days with the ozone and it was fine after.

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If it still smelled it is because the waste of the mice remained in the RV. The ozone didn't remove the waste, but probably just reacted with it to neutralize the odor causing VOCs.

If you were ok with that state, that's great, but eliminating the source of the odor tends to be more effective way to deal with it.

It kills off microbes, does it not? We live in a high humidity environment. When we shut up the house and travel for a couple weeks, there's inevitably a high amount of mildew on our return. I have been contemplating running an ozone generator on a timer while we're out of the house for an extended period to combat this.

> I have been contemplating running an ozone generator on a timer while we're out of the house for an extended period to combat this.

You would be treating the symptom, not the cause, with a harmful chemical that probably wouldn't completely eliminate the mildew, and have unknown side effects.

It would be far better to install a dehumidifier and proper ventilation to manage the mildew problem than killing it off with ozone afterwards.

The house isn't sealed to the outside, and we don't typically run AC (or heat). A dehumidifer would just run all day and produce water without affecting the humidity in the house at all (again, because it's not sealed). Very different from US or European build quality. And yes, ozone would leak to the outside, but most of the venting happens from the top of the house.

(For reference, there's a $50m house nearby for sale that has no exterior walls at all. It's being sold at a discount - only $12m! - because of a notorious incident that took place there, and the fact that the owner can't return to the country without risking arrest and a fourth trial.)

> The house isn't sealed to the outside, and we don't typically run AC (or heat).

Sounds like you are in or near the tropics. How do you control the mildew when you are at home? Presumably not with ozone, but with ventilation. Can you just have the house do that when you are not there also?

Yeah. Windows and doors open when we're home, typically (with ceiling fans to move the air). We definitely _could_ install whole house ventilation and leave that running, you're right - it'd just need to be done well, so could be spendy.

Have you considered something like Mitsubishi Lossnay[1]? The unit itself is not expensive. Also much cheaper to run than aircon and better for the environment.

We’re also in a high humidity environment with equally breezy construction standards and have struggled to keep the house mildew-free when we travel in Summer. We eventually settled on running a compressor-dehumidifier 24/7 during those times, but it’s not perfect.

We considered installing a Lossnay to create a consistent positive pressure gradient and help with humidity exchange, although in our case construction - although not extensive - is tricky as we’re quite high up. You might be better off.

[1] https://sg.mitsubishielectric.com/en/products-solutions/air-...

It looks interesting - thanks. I'll investigate further.

According to you, I should have removed every bit of structural material and flooring because the ozone "only" neutralized it? You do realize odors are VOCs, right? Ozone destroyed them. It's great.

> You do realize odors are VOCs, right?

Odors are caused by some VOCs. Some VOCs have no odor, including harmful ones.

> Ozone destroyed them.

https://pubs.acs.org/doi/full/10.1021/acs.estlett.1c00773

Conclusion:

"... this work shows that for at least some consumer-grade portable air cleaners that claim to remove VOCs from indoor air, VOC removal may actually be minimal, and the air delivered may contain additional VOCs and/or oxidation byproducts, some of which are known to be harmful to human health."

I worry about ozone generators degrading electrical components, especially wiring insulation and sensors.

That's generally a non-issue if used occasionally and at reasonable levels.

Worked well for me as well in mildew-y car, still had a smell after replacing all carpet and cleaning every reachable surface. Ozone with air running for an hour resolved it nicely.

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